In data communication systems, it is often useful to modularize interface electronics and other interface elements in a data communication module. For example, in an optical data communication system, an opto-electronic transceiver module may include a light source such as a laser, and a light receiver such as a photodiode, and may also include driver and receiver circuitry associated with the laser and photodiode. To use such an opto-electronic transceiver module, an optical fiber cable is plugged into a port in the module. Such a module also includes electrical contacts that can be coupled to an external electronic system.
Another example of a data communication module is an Ethernet transceiver module. To use an Ethernet transceiver module, an Ethernet cable, which may have an electrical rather than an optical connector, is plugged into a port in the module. The module may include signal conditioning electronics. Such a module also includes electrical contacts that can be coupled to an external electronic system.
Some data communication modules are configured to be plugged into a cage or other receptacle. A standard communication module configuration commonly referred to in the art as Small Form Factor Pluggable (SFP) includes an elongated housing having a generally rectangular profile. An SFP module is pluggable into a metallic cage that shields the module against electromagnetic interference (EMI). A latching mechanism retains the SFP module in the EMI cage. The latching mechanism typically includes a bail that can be pivoted or flipped between a latched position in which the bail lies against the forward end of the module and an unlatched position in which the bail extends outwardly away from the module.
The latching mechanism of an SFP module typically comprises a pin on the module housing and a catch on the cage. As the module is inserted into the cage, the pin engages an opening in the catch to latch the module in place in the cage. To release or unlatch the module from the cage, the bail is flipped or pivoted downwardly to the above-described unlatched position, which disengages the pin and the catch from each other by moving one of the pin or the catch relative to the other. The outwardly extending bail can then be used as a handle to withdraw the module from the cage. Prior latching mechanisms for SFP modules generally fall into two categories: moving catch and moving pin.
A moving-catch latching mechanism unlatches the pin from the catch by flexing the catch away from the pin in response to the downward motion of the bail so that the pin and catch do not interfere with each other when the module is withdrawn from the cage. Moving-catch latching mechanisms promote manufacturing efficiency by minimizing the number of parts. However, moving-catch latching mechanisms suffer from dependence upon the resilience or flexibility of the catch.
A moving-pin latching mechanism de-latches the pin from the catch by causing the pin to retract into the module housing in response to the pivoting motion of the bail so that the pin and catch do not interfere with each other when the module is withdrawn from the cage. Moving-pin latching mechanisms do not depend upon flexibility of the catch and provide low frictional resistance between the pin and catch. However, prior moving-pin latching mechanisms can be complex, involving a substantial number of moving parts, resulting in manufacturing inefficiency.